Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc109cb691937bd7…

MALICIOUS

PDF

68.4 KB Created: 2021-04-29 01:12:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: de351c3ad36ec8d26edf402739d77ee9 SHA-1: 61cd90b6176313f80a94dda9e50d3b0816c62ee6 SHA-256: fc109cb691937bd71fe9e91e63f21b7e68a6789a1cec2d25a2309ddd620e030e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple links to external websites, many hosted on compromised CMS platforms, suggesting a link farm intended to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to leverage web content for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://unique.global/wp-content/plugins/super-forms/uploads/php/files/e7813384235bebdf2cbec95543dc2d71/53723182400.pdf
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe73d0b135---raduranaxideposabu.pdf
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/5k7mtljc1ls0ofek55vkd94sb7/silekokisoxilamupe.pdf
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16078da3b2efd4---41838632742.pdf
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/7b26b5dfa6675f4aa6088a7b42fe036a/40551740113.pdf
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/cova9j4sj09b0quag5citpqef7/jajatanapukexelew.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/160801bd30c020---24910494881.pdf
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/e517c6dad6432ddea453db34ab929d50/54301564683.pdf
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088b27e8667c---36124628026.pdf
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/9e6kvgr9hffmm5ntsurs611bh5/jewilasewepu.pdf
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/0f96192314f3edc995955eec5a0ad991/1550374541.pdf
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/16078e903236e1---xeduder.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075a5169b12d---33306750898.pdf
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085286334eba---zajalara.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=math+shapes+for+kindergarten+worksheets
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf21.bin
355a3575eae94b0b9fe7e27761588ae7766a843727c201515190ec99ecc384ea
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF21 5432 bytes
font_01_sfnt_off0000e1b8.bin
49ae4bb776670ef1067bf18cddf2d1c5a849e99c9f96799aabaf05c7cfb72d05
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B8 10220 bytes